Semiconductor device

ABSTRACT

A semiconductor device includes a first planar semiconductor (e.g., silicon) layer, first and second pillar-shaped semiconductor (e.g., silicon) layers, a first gate insulating film, a first gate electrode, a second gate insulating film, a second gate electrode, a first gate line connected to the first and second gate electrodes, a first n-type diffusion layer, a second n-type diffusion layer, a first p-type diffusion layer, and a second p-type diffusion layer. A center line extending along the first gate line is offset by a first predetermined amount from a line connecting a center of the first pillar-shaped semiconductor layer and a center of the second pillar-shaped semiconductor layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of copending patent application Ser.No. 13/893,560, filed May 14, 2013; which claimed the benefit, under 35U.S.C. §119(e), of provisional patent application No. 61/649,442 filedMay 21, 2012; the prior applications are herewith incorporated byreference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a semiconductor device.

Semiconductor integrated circuits, particularly integrated circuitsusing MOS transistors, are increasing in integration. With increases inintegration, MOS transistors become finer up to a nano-level. Such finerMOS transistors have difficulty in suppressing leak currents anddifficulty in decreasing areas occupied by circuits in view of thedemand for securing necessary amounts of currents. In order to resolvethe problem, there are proposed surrounding gate transistors (referredto as “SGT” hereinafter) having a structure in which a source, gate, anddrain are disposed perpendicularly to a substrate, and a gate electrodesurrounds a pillar-shaped semiconductor layer (for example, refer toJapanese Unexamined Patent Application Publication Nos. 2-71556,2-188966, and 3-145761).

Also, there is proposed a structure in which a CMOS inverter is formedby using the SGT so that n-type SGT and p-type SGT are disposed on aline and diffusion layers positioned at the bottom portions of siliconpillars are used as the output of the inverter (refer to, for example,Japanese Unexamined Patent Application Publication No. 2008-205168). Inthis structure, a connection region of ohmic junction with p- andn-regions containing impurities is formed in a surface of an elementformation region, and the connection region is electrically connected tovias for output signals outside the n-type SGT and p-type SGT.

This technique cannot establish a method for forming the connectionregion because the width of gate line is larger than the width of theelement formation region.

In this technique, forming a connection region with silicide requires aprotective film to be used for silicidization and a sidewall to beformed around the gate line in order to prevent short circuiting.

Therefore, when silicide is formed on portions of an element formationregion around both opposing sides of gate line, it is necessary that thewidth of the element formation region is wider than the total of thewidth of the gate line and a length of twice the width of the side wall.In this case, the area occupied by the element formation region isincreased.

Further, SRAM (Static Random Access Memory) using six SGTs is proposed(refer to, for example, International Publication No. 2009/095998). Inthis literature, the width of an element formation region is wider thanthe total of the width of gate line and a length of twice the width of asidewall, and silicide is formed on portions of the element formationregion which are present around both opposing sides of the gate line. Inthis case, the area occupied by the element formation region isincreased.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a semiconductor devicehaving a small area occupied by an element formation region and usingCMOS SGT.

A semiconductor device in a first aspect of the present inventionincludes:

a first planar silicon layer formed on a substrate;

first and second pillar-shaped silicon layers formed on the first planarsilicon layer;

a first gate insulating film formed around the first pillar-shapedsilicon layer;

a first gate electrode formed around the first gate insulating film;

a second gate insulating film formed around the second pillar-shapedsilicon layer;

a second gate electrode formed around the second gate insulating film;

a first gate line connected to the first and second gate electrodes;

a first second-conductivity-type diffusion layer formed in an upperportion of the first pillar-shaped silicon layer;

a second second-conductivity-type diffusion layer formed over a lowerportion of the first pillar-shaped silicon layer and an upper portion ofthe planar silicon layer;

a first first-conductivity-type diffusion layer formed in an upperportion of the second pillar-shaped silicon layer; and

a second first-conductivity-type diffusion layer formed over a lowerportion of the second pillar-shaped silicon layer and an upper portionof the planar silicon layer,

wherein a center line extending along the first gate line is offset by afirst predetermined amount from a line connecting a center of the firstpillar-shaped silicon layer and a center of the second pillar-shapedsilicon layer.

The semiconductor device further includes:

a first insulating film sidewall formed on the sidewall of the firstgate line; and

a silicide formed over the second second-conductivity-type diffusionlayer and the second first-conductivity-type diffusion layer,

wherein the first predetermined amount is preferably larger than a valueobtained by subtracting a length of half the width of the first planarsilicon layer from the total of the width of the first insulating filmsidewall and a length of half the width of the first gate line.

The first predetermined amount is preferably larger than a valueobtained by subtracting the total of the width of the first insulatingfilm sidewall and a length of half the width of the first gate line fromthe width of the first planar silicon layer.

The semiconductor device preferably further includes:

a second insulating film sidewall formed over an upper sidewall of thefirst pillar-shaped silicon layer and an upper portion of the first gateelectrode;

a third insulating film sidewall formed over an upper sidewall of thesecond pillar-shaped silicon layer and an upper portion of the secondgate electrode;

a first insulating film sidewall formed over the second and thirdinsulating film sidewalls, the first and second gate electrodes, and asidewall of the first gate line; and

a silicide formed over the first second-conductivity-type diffusionlayer and the first first-conductivity-type diffusion layer.

With the above and other objects in view there is also provided, inaccordance with a second embodiment of the invention, a semiconductorwhich comprises the following elements:

an 11th (first) planar silicon layer formed in the first row ofcoordinates of rows and columns arranged on a substrate so as to extendin the row direction;

an 11th (first) pillar-shaped silicon layer formed on the 11th (first)planar silicon layer to be disposed in the first row and the firstcolumn of the coordinates;

an 11th (first) gate insulating film formed around the 11th (first)pillar-shaped silicon layer;

an 11th (first) gate electrode formed around the 11th (first) gateinsulating film;

an 11th (first) second-conductivity-type diffusion layer formed in anupper portion of the 11th (first) pillar-shaped silicon layer;

a 12th (second) second-conductivity-type diffusion layer formed over alower portion of the 11th (first) pillar-shaped silicon layer and anupper portion of the 11th (first) planar silicon layer;

a 12th (second) pillar-shaped silicon layer formed on the 11th (first)planar silicon layer to be disposed in the first row and the secondcolumn of the coordinates;

a 12th (second) gate insulating film formed around the 12th (second)pillar-shaped silicon layer;

a 12th (second) gate electrode formed around the 12th (second) gateinsulating film;

an 11th (first) first-conductivity-type diffusion layer formed in anupper portion of the 12th (second) pillar-shaped silicon layer;

a 12th (second) first-conductivity-type diffusion layer formed over alower portion of the 12th (second) pillar-shaped silicon layer and anupper portion of the 11th (first) planar silicon layer;

a 13th (third) pillar-shaped silicon layer formed on the 11th (first)planar silicon layer to be disposed in the first row and the thirdcolumn of the coordinates;

a 13th (third) gate insulating film formed around the 13th (third)pillar-shaped silicon layer;

a 13th (third) gate electrode formed around the 13th (third) gateinsulating film;

a 13th (third) second-conductivity-type diffusion layer formed in anupper portion of the 13th (third) pillar-shaped silicon layer;

a 14th (fourth) (fourth) second-conductivity-type diffusion layer formedover a lower portion of the 13th (third) pillar-shaped silicon layer andan upper portion of the 11th (first) planar silicon layer;

an 11th (first) gate line connected to the 11th (first) and 12th(second) gate electrodes;

a 21st (fifth) planar silicon layer formed in the second row of thecoordinates arranged on the substrate;

a 21st (fifth) pillar-shaped silicon layer formed on the 21st (fifth)planar silicon layer to be disposed in the second row and the firstcolumn of the coordinates;

a 21st (fifth) gate insulating film formed around the 21st (fifth)pillar-shaped silicon layer;

a 21st (fifth) gate electrode formed around the 21st (fifth) gateinsulating film;

a 21st (fifth) second-conductivity-type diffusion layer formed in anupper portion of the 21st (fifth) pillar-shaped silicon layer;

a 22nd (sixth) second-conductivity-type diffusion layer formed over alower portion of the 21st (fifth) pillar-shaped silicon layer and anupper portion of the 21st (fifth) planar silicon layer;

a 22nd (sixth) pillar-shaped silicon layer formed on the 21st (fifth)planar silicon layer to be disposed in the second row and the secondcolumn of the coordinates;

a 22nd (sixth) gate insulating film formed around the 22nd (sixth)pillar-shaped silicon layer;

a 22nd (sixth) gate electrode formed around the 22nd (sixth) gateinsulating film;

a 21st (fifth) first-conductivity-type diffusion layer formed in anupper portion of the 22nd (sixth) pillar-shaped silicon layer;

a 22nd (sixth) first-conductivity-type diffusion layer formed over alower portion of the 22nd (sixth) pillar-shaped silicon layer and anupper portion of the 21st (fifth) planar silicon layer;

a 23rd (seventh) (seventh) pillar-shaped silicon layer formed on the21st (fifth) planar silicon layer to be disposed in the second row andthe third column of the coordinates;

a 23rd (seventh) (seventh) gate insulating film formed around the 23rd(seventh) pillar-shaped silicon layer;

a 23rd (seventh) gate electrode formed around the 23rd (seventh) gateinsulating film;

a 23rd (seventh) second-conductivity-type diffusion layer formed in anupper portion of the 23rd (seventh) pillar-shaped silicon layer;

a 24th (eighth) second-conductivity-type diffusion layer formed over alower portion of the 23rd (seventh) pillar-shaped silicon layer and anupper portion of the 21st (fifth) planar silicon layer; and

a 21st (fifth) gate line connected to the 22nd (sixth) and 23rd(seventh) gate electrodes,

wherein a center line extending along the 11th (first) gate line isoffset to the second row of the coordinates by an 11th (first)predetermined amount from a line connecting a center of the 11th (first)pillar-shaped silicon layer and a center of the 12th (second)pillar-shaped silicon layer; and

a center line extending along the 21st (fifth) gate line is offset tothe first row of the coordinates by the 11th (first) predeterminedamount from a line connecting a center of the 22nd (sixth) pillar-shapedsilicon layer and a center of the 23rd (seventh) pillar-shaped siliconlayer.

The semiconductor device further includes:

an 11th (first) insulating film sidewall formed on a sidewall of the11th (first) gate line; and

a silicide formed over the 12th (second) second-conductivity-typediffusion layer and the 12th (second) first-conductivity-type diffusionlayer,

wherein the 11th (first) predetermined amount is preferably larger thana value obtained by subtracting a length of half the width of the 11th(first) planar silicon layer from the total of the width of the 11th(first) insulating film sidewall and a length of half the width of the11th (first) gate line.

A 11th (first) contact is formed over a portion between the 11th (first)pillar-shaped silicon layer and the 12th (second) pillar-shaped siliconlayer and a portion between the 21st (fifth) pillar-shaped silicon layerand the 22nd (sixth) pillar-shaped silicon layer; and the 11th (first)gate line is preferably electrically connected to the 21st (fifth)planar silicon layer through the 11th (first) contact.

The 11th (first) predetermined amount is preferably larger than a valueobtained by subtracting the total of the width of the 11th (first)insulating film sidewall and a length of half the width of the 11th(first) gate line from the width of the 11th (first) planar siliconlayer.

According to the present invention, a semiconductor device having asmall area occupied by an element formation region and using CMOS SGTcan be provided.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a semiconductor device, it is nevertheless not intended to be limitedto the details shown, since various modifications and structural changesmay be made therein without departing from the spirit of the inventionand within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1(A) is a plan view of a semiconductor device according to anembodiment of the present invention, FIG. 1(B) is a sectional view takenalong line X3-X3′ in FIG. 1(A), FIG. 1(C) is a sectional view takenalong line Y3-Y3′ in FIG. 1(A), and FIG. 1(D) is a sectional view takenalong line Y4-Y4′ in FIG. 1(A).

FIG. 2(A) is a plan view of a semiconductor device according to anembodiment of the present invention, FIG. 2(B) is a sectional view takenalong line X1-X1′ in FIG. 2(A), and FIG. 2(C) is a sectional view takenalong line Y1-Y1′ in FIG. 2(A).

FIG. 3(A) is a plan view of a semiconductor device according to anembodiment of the present invention, FIG. 3(B) is a sectional view takenalong line X2-X2′ in FIG. 3(A), and FIG. 3(C) is a sectional view takenalong line Y2-Y2′ in FIG. 3(A).

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures of the drawing in detail and first,particularly, to FIG. 1 thereof, there is shown a semiconductor deviceaccording to an embodiment of the present invention that includes afirst planar silicon layer 309 formed on a substrate 501, and first andsecond pillar-shaped silicon layers 504 and 505 formed on the firstplanar silicon layer 309.

The semiconductor device according to the embodiment of the presentinvention further includes a first gate insulating film 506 formedaround the first pillar-shaped silicon layer 504, and a first gateelectrode 303 formed around the first gate insulating film 506.

The semiconductor device according to the embodiment of the presentinvention further includes a second gate insulating film 506 formedaround the second pillar-shaped silicon layer 505, a second gateelectrode 304 formed around the second gate insulating film 506, a firstgate line 305 connected to the first and second gate electrodes 303 and304, a first n-type diffusion layer 524 formed in an upper portion ofthe first pillar-shaped silicon layer 504, a second n-type diffusionlayer 502 formed over a lower portion of the first pillar-shaped siliconlayer 504 and an upper portion of the planar silicon layer 309, a firstp-type diffusion layer 525 formed in an upper portion of the secondpillar-shaped silicon layer 505, and a second p-type diffusion layer 503formed over a lower portion of the second pillar-shaped silicon layer505 and an upper portion of the planar silicon layer 309.

In the semiconductor device according to the embodiment of the presentinvention, a center line extending along the first gate line 305, infurther detail, a center line extending horizontally along the firstgate line 305 and passing through the center of the first gate line 305in the width direction thereof, is offset by a first predeterminedamount from a line connecting the center of the first pillar-shapedsilicon layer 504 and the center of the second pillar-shaped siliconlayer 505.

Herein, an insulating film used for semiconductors, such as an oxidefilm, a nitride film, an oxynitride film, or a high-dielectric film, canbe used as a material for the gate insulating film 506.

The semiconductor device according to the embodiment of the presentinvention can produce the advantages described below due to theabove-described characteristics.

That is, a silicide 308 can be formed on a portion of the planar siliconlayer 309 serving as an element formation region, the portion beingpresent around a first side of the first gate line 305, therebypermitting electric connection between the second n-type diffusion layer502 of n-type SGT and the second p-type diffusion layer 503 of p-typeSGT. Therefore, the width of the planar silicon layer 309 serving as theelement formation region can be narrowed as compared with a case where asilicide is formed on portions of an element formation region which arepresent around first and second opposing sides of a gate line.

In addition, since the planar silicon layer serving as the elementformation region has a narrow width, a highly-integrated CMOS SGTinverter can be realized.

In the semiconductor device according to the embodiment of the presentinvention, as shown in FIG. 1, the first pillar-shaped silicon layer 504forms n-type SGT 301, and the second pillar-shaped silicon layer 505forms p-type SGT 302.

The semiconductor device according to the embodiment of the presentinvention includes a first insulating film sidewall 307 formed on thesidewall of the first gate line 305, and the silicide 308 formed overthe second n-type diffusion layer 502 and the second p-type diffusionlayer 503.

The first predetermined amount is larger than a value obtained bysubtracting a length of half the width of the first planar silicon layer309 from the total of the width of the first insulating film sidewall307 and a length of half the width of the first gate line 305.

The first predetermined amount is larger than a value obtained bysubtracting the total of the width of the first insulating film sidewall307 and a length of half the width of the first gate line 305 from alength of half the width of the first planar silicon layer 309.

According to the semiconductor device according to the embodiment of thepresent invention, due to the above-described characteristics, asilicide can be formed on a portion of a planar silicon layer serving asan element formation region, the portion being formed around a firstside of gate line.

The semiconductor device according to the embodiment of the presentinvention includes the first gate electrode 303 formed around the firstgate insulating film 506 and having a laminated structure including ametal film 507 and polysilicon 509, and the second gate electrode 304formed around the second gate insulating film 506 and having a laminatedstructure including the metal film 507 and the polysilicon 509.

A gate may be made of only a metal film or silicide. In addition, ametal used for semiconductors, such as titanium, titanium nitride,tantalum, or tantalum nitride, can be used for the metal film.

In the semiconductor device according to the embodiment of the presentinvention, a gate line 306 is formed to be connected to the first gateelectrode 303.

The semiconductor device according to the embodiment of the presentinvention includes a second insulating film sidewall including an oxidefilm 516 and a nitride film 517 and formed over an upper sidewall of thefirst pillar-shaped silicon layer 504 and an upper portion of the firstgate electrode 303, a third insulating film sidewall including an oxidefilm 518 and a nitride film 519 and formed over an upper sidewall of thesecond pillar-shaped silicon layer 505 and an upper portion of thesecond gate electrode 304, the first insulating film sidewall 307 formedover the second and third insulating film sidewalls, the first andsecond gate electrodes 303 and 304, and the sidewalls of the first gateline 305 and the gate line 306, and silicides 511 and 513 formed overthe first n-type diffusion layer 524 and the first p-type diffusionlayer 525.

In the semiconductor device according to the embodiment of the presentinvention, an upper portion of the second gate electrode 304 is coveredwith the third insulating film sidewall 518, 519, and the sidewall iscovered with the first insulating film sidewall 307. The sidewall of thethird insulating film sidewall 518, 519 is covered with the firstinsulating sidewall 307. Therefore, when a contact 523 formed on adiffusion layer in an upper portion of the planar silicon layer 309 isoffset to the second gate electrode 304, short-circuiting between thesecond gate electrode 304 and the contact 523 can be prevented.

Further, a silicide 510 is formed on the gate line 306, and a silicide512 is formed on the first gate line 305. In addition, a silicide 514 isformed on the second p-type diffusion layer 503. Further, a contact 520,a contact 521, a contact 522, and a contact 523 are formed on thesilicide 510, the silicide 511, the silicide 513, and the silicide 514,respectively.

Further, an element separation film 508 is formed around the firstplanar silicon layer 309, and interlayer insulating film 515 is formedaround each of the n-type SGT 301 and the p-type SGT 302.

Next, FIGS. 2 and 3 show a structure in which the semiconductor deviceaccording to the embodiment is applied to SRAM.

As shown in FIGS. 2 and 3, the semiconductor device according to theembodiment includes, in the first row of coordinates of rows and columnsarranged on a substrate 201, an 11th (first) planar silicon layer 121extending in the row direction, an 11th (first) pillar-shaped siliconlayer 208 formed on the 11th (first) planar silicon layer 121 to bedisposed in the first row and the first column of the coordinates on thesubstrate 201, an 11th (first) gate insulating film 215 formed aroundthe 11th (first) pillar-shaped silicon layer 208, and an 11th (first)gate electrode 107 formed around the 11th (first) gate insulating film215.

The semiconductor device according to the embodiment further includesn-type SGT 101 including an 11th (first) n-type diffusion layer 227formed in an upper portion of the 11th (first) pillar-shaped siliconlayer 208 and a 12th (second) n-type diffusion layer 202 formed over alower portion of the 11th (first) pillar-shaped silicon layer 208 and anupper portion of the 11th (first) planar silicon layer 121, a 12th(second) pillar-shaped silicon layer 209 formed on the 11th (first)planar silicon layer 121 to be disposed in the first row and the secondcolumn of the coordinate on the substrate 201, a 12th (second) gateinsulating film 215 formed around the 12th (second) pillar-shapedsilicon layer 209, and a 12th (second) gate electrode 108 formed aroundthe 12th (second) gate insulating film 215.

The semiconductor device according to the embodiment further includesp-type SGT 102 including an 11th (first) p-type diffusion layer 228formed in an upper portion of the 12th (second) pillar-shaped siliconlayer 209 and a 12th (second) p-type diffusion layer 203 formed over alower portion of the 12th (second) pillar-shaped silicon layer 209 andan upper portion of the 11th (first) planar silicon layer 121, a 13th(third) pillar-shaped silicon layer 210 formed on the 11th (first)planar silicon layer 121 to be disposed in the first row and the thirdcolumn of the coordinates on the substrate 201, a 13th (third) gateinsulating film 217 formed around the 13th (third) pillar-shaped siliconlayer 210, and a 13th (third) gate electrode 109 formed around the 13th(third) gate insulating film 217.

The semiconductor device according to the embodiment further includesn-type SGT 103 including a 13th (third) n-type diffusion layer 229formed in an upper portion of the 13th (third) pillar-shaped siliconlayer 210 and a 14th (fourth) (fourth) n-type diffusion layer 204 formedover a lower portion of the 13th (third) pillar-shaped silicon layer 210and an upper portion of the 11th (first) planar silicon layer 121, andan 11th (first) gate line 113 connected to the 11th (first) and 12th(second) gate electrodes 107 and 108.

The semiconductor device according to the embodiment further includes,in the second row of the coordinates on the substrate 201, a 21st(fifth) planar silicon layer 122 extending in the row direction, a 21st(fifth) pillar-shaped silicon layer 211 formed on the 21st (fifth)planar silicon layer 122 to be disposed in the second row and the firstcolumn of the coordinates on the substrate 201, a 21st (fifth) gateinsulating film 219 formed around the 21st (fifth) pillar-shaped siliconlayer 211, and a 21st (fifth) gate electrode 110 formed around the 21st(fifth) gate insulating film 219.

The semiconductor device according to the embodiment further includesn-type SGT 104 including a 21st (fifth) n-type diffusion layer 230formed in an upper portion of the 21st (fifth) pillar-shaped siliconlayer 211 and a 22nd (sixth) n-type diffusion layer 205 formed over alower portion of the 21st (fifth) pillar-shaped silicon layer 211 and anupper portion of the 21st (fifth) planar silicon layer 122, a 22nd(sixth) pillar-shaped silicon layer 212 formed on the 21st (fifth)planar silicon layer 122 to be disposed in the second row and the secondcolumn of the coordinates, a 22nd (sixth) gate insulating film 221formed around the 22nd (sixth) pillar-shaped silicon layer 212, and a22nd (sixth) gate electrode 111 formed around the 22nd (sixth) gateinsulating film 221.

The semiconductor device according to the embodiment further includesp-type SGT 105 including a 21st (fifth) p-type diffusion layer 231formed in an upper portion of the 22nd (sixth) pillar-shaped siliconlayer 212 and a 22nd (sixth) p-type diffusion layer 206 formed over alower portion of the 22nd (sixth) pillar-shaped silicon layer 212 and anupper portion of the 21st (fifth) planar silicon layer 122, a 23rd(seventh) pillar-shaped silicon layer 213 formed on the 21st (fifth)planar silicon layer 122 to be disposed in the second row and the thirdcolumn of the coordinates, a 23rd (seventh) gate insulating film 221formed around the 23rd (seventh) pillar-shaped silicon layer 213, and a23rd (seventh) gate electrode 112 formed around the 23rd (seventh) gateinsulating film 221.

The semiconductor device according to the embodiment further includesn-type SGT 106 including a 23rd (seventh) n-type diffusion layer 232formed in an upper portion of the 23rd (seventh) pillar-shaped siliconlayer 213 and a 24th (eighth) n-type diffusion layer 207 formed over alower portion of the 23rd (seventh) pillar-shaped silicon layer 213 andan upper portion of the 21st (fifth) planar silicon layer 122, and a21st (fifth) gate line 116 connected to the 22nd (sixth) and 23rd(seventh) gate electrodes 111 and 112.

In the semiconductor device according to the embodiment of the presentinvention, a center line extending along the 11th (first) gate line 113is offset by an 11th (first) predetermined amount from a line connectingthe center of the 11th (first) pillar-shaped silicon layer 208 and thecenter of the 12th (second) pillar-shaped silicon layer 209 to thesecond row of the coordinates on the substrate 201.

Also in the semiconductor device according to the embodiment of thepresent invention, a center line extending along the 21st (fifth) gateline 116 is offset by the 11th (first) predetermined amount from a lineconnecting the center of the 22nd (sixth) pillar-shaped silicon layer212 and the center of the 23rd (seventh) pillar-shaped silicon layer 213to the first row of the coordinates on the substrate 201.

The semiconductor device according to the embodiment further includes an11th (first) insulating film sidewall 127 formed on the sidewall of the11th (first) gate line 113, and a silicide 117 formed on the 12th(second) n-type diffusion layer 202 and the 12th (second) p-typediffusion layer 203. The 11th (first) predetermined amount is largerthan a value obtained by subtracting a length of half the width of the11th (first) planar silicon layer 121 from the total of the width of the11th (first) insulating film sidewall 127 and a length of half the widthof the 11th (first) gate line 113.

In the embodiment, an 11th (first) contact 124 is formed over a portionbetween the 11th (first) pillar-shaped silicon layer 208 and the 12th(second) pillar-shaped silicon layer 209 and a portion between the 21st(fifth) pillar-shaped silicon layer 211 and the 22nd (sixth)pillar-shaped silicon layer 212. The 11th (first) contact 124electrically connects the 11th (first) gate line 113 and the 21st(fifth) planar silicon layer 122.

Also in the embodiment, the 11th (first) predetermined amount is largerthan a value obtained by subtracting the total of the width of the 11th(first) insulating film sidewall 127 and a length of half the width ofthe 11th (first) gate line 113 from a length of half the width of the11th (first) planar silicon layer 121.

In the embodiment, a silicide is formed on a portion of the 11th (first)planar silicon layer 121 serving as an element formation region, theportion being present around a first side of the 11th (first) gate line113, thereby permitting electric connection between the 12th (second)n-type diffusion layer 202 of the n-type SGT 101 and the 12th (second)p-type diffusion layer 203 of the p-type SGT 102.

The embodiment has a structure in which a portion of the 11th (first)planar silicon layer 121 serving as an element formation region, theportion being present around a second side of the 11th (first) gate line113, is covered with the 11th (first) gate line 113 and the 11th (first)insulating film sidewall 127.

Therefore, according to the embodiment, the 11th (first) contact 124 isformed over a portion between the 11th (first) pillar-shaped siliconlayer 208 and the 12th (second) pillar-shaped silicon layer 209 and aportion between the 21st (fifth) pillar-shaped silicon layer 211 and the22nd (sixth) pillar-shaped silicon layer 212, thereby permitting the11th (first) gate line 113 and the 21st (fifth) planar silicon layer 122to be electrically connected to each other through the 11th (first)contact 124 and the 11th (first) planar silicon layer 121 and the 11th(first) contact 124 to be insulated from each other.

According to the embodiment, input and output of a SRAM inverter can beelectrically connected to each other through the 11th (first) contact124. As a result, a highly integrated SRAM can be provided.

In the embodiment, an insulating film used for semiconductors, such asan oxide film, a nitride film, an oxynitride film, or a high-dielectricfilm, can be used for the gate insulating film 221.

The semiconductor device according to the embodiment of the presentinvention further includes the 11th (first) gate electrode 107 formedaround the 11th (first) gate insulating film 215 and having a laminatedstructure including a metal film 216 and polysilicon 223, the 12th(second) gate electrode 108 formed around the 12th (second) gateinsulating film 215 and having a laminated structure including the metalfilm 216 and the polysilicon 223, and the 13th (third) gate electrode109 formed around the 13th (third) gate insulating film 217 and having alaminated structure including a metal film 218 and polysilicon 224. Thegate may be made of only a metal film. Alternatively, a silicide may beused as a material of the gate. In addition, a metal used forsemiconductors, such as titanium, titanium nitride, tantalum, ortantalum nitride, can be used for the metal film.

A gate line 114 is formed to be connected to the 13th (third) gateelectrode 109.

The semiconductor device according to the embodiment of the presentinvention further includes an insulating film sidewall including anoxide film 244 and a nitride film 245 and formed over an upper sidewallof the 11th (first) pillar-shaped silicon layer 208 and an upper portionof the 11th (first) gate electrode 107, an insulating film sidewallincluding an oxide film 246 and a nitride film 247 and formed over anupper sidewall of the 12th (second) pillar-shaped silicon layer 209 andan upper portion of the 12th (second) gate electrode 108, an insulatingfilm sidewall including an oxide film 248 and a nitride film 249 andformed over an upper sidewall of the 13th (third) pillar-shaped siliconlayer 210 and an upper portion of the 13th (third) gate electrode 109,and silicides 234, 236, and 237 formed over the 11th (first) n-typediffusion layer 227, the 11th (first) p-type diffusion layer 228, andthe 13th (third) n-type diffusion layer 229.

A silicide 118 is formed over the 12th (second) n-type diffusion layer203 and the 14th (fourth) (fourth) n-type diffusion layer 204, and asilicide 235 is formed on the 11th (first) gate line 113. In addition, asilicide 238 is formed on the gate line 114.

An insulating film sidewall 128 is formed on the sidewall of the gateline 114.

Further, a contact 257, a contact 258, and a contact 259 are formed onthe silicide 234, the silicide 236, and the silicide 237, respectively.

The semiconductor device according to the embodiment of the presentinvention further includes the 21st (fifth) gate electrode 110 formedaround the 21st (fifth) gate insulating film 219 and having a laminatedstructure including a metal film 220 and polysilicon 225, the 22nd(sixth) gate electrode 111 formed around the 22nd (sixth) gateinsulating film 221 and having a laminated structure including a metalfilm 222 and polysilicon 226, and the 23rd (seventh) gate electrode 112formed around the 23rd (seventh) gate insulating film 221 and having alaminated structure including the metal film 222 and the polysilicon226.

The gate may be made of only a metal film. Alternatively, a silicide maybe used for the gate. In addition, a metal used for semiconductors, suchas titanium, titanium nitride, tantalum, or tantalum nitride, can beused for the metal film.

Also in the embodiment, a gate line 115 is formed to be connected to the21st (fifth) gate electrode 110.

The semiconductor device according to the embodiment of the presentinvention further includes an insulating film sidewall including anoxide film 250 and a nitride film 251 and formed over an upper sidewallof the 21st (fifth) pillar-shaped silicon layer 211 and an upper portionof the 21st (fifth) gate electrode 110, an insulating film sidewallincluding an oxide film 252 and a nitride film 253 and formed over anupper sidewall of the 22nd (sixth) pillar-shaped silicon layer 212 andan upper portion of the 22nd (sixth) gate electrode 111, an insulatingfilm sidewall including an oxide film 254 and a nitride film 255 andformed over an upper sidewall of the 23rd (seventh) pillar-shapedsilicon layer 213 and an upper portion of the 23rd (seventh) gateelectrode 112, and silicides 240, 241, and 243 formed on the 21st(fifth) n-type diffusion layer 230, the 21st (fifth) p-type diffusionlayer 231, and the 23rd (seventh) n-type diffusion layer 232.

In the embodiment, a silicide 119 is formed over the 22nd (sixth) n-typediffusion layer 205 and the 22nd (sixth) p-type diffusion layer 206, anda silicide 242 is formed on the 21st (fifth) gate line 116. In addition,a silicide 239 is formed on the gate line 115.

A silicide 120 is formed over the 22nd (sixth) p-type diffusion layer206 and the 24th (eighth) n-type diffusion layer 207.

An insulating film sidewall 129 is formed on the sidewall of the gateline 115. An insulating film sidewall 130 is formed on the sidewall ofthe 21st (fifth) gate line 116.

Further, a contact 260, a contact 261, and a contact 262 are formed onthe silicide 240, the silicide 241, and the silicide 243, respectively.

Further, a contact 123, an 11th (first) contact 124, a contact 125, anda contact 126 are formed on the silicide 239, the silicides 235 and 119,the silicide 118 and 242, and the silicide 238, respectively.

An element separation region 214 is formed around the 11th (first)planar silicon layer 121 and the 21st (fifth) planar silicon layer 122.In addition, an interlayer insulating film 256 is formed around then-type SGTs 101, 103, 104, and 106, and the p-type SGTs 102 and 104.

According to the embodiment, the above-described configuration permitselectric connection between input and output of a SRAM inverter throughthe 11th (first) contact 124, and thus highly integrated SRAM can beprovided.

In the above-described embodiment of the present invention, the centerline extending along the first gate line is offset by the firstpredetermined amount from the line connecting the center of the firstpillar-shaped silicon layer and the second pillar-shaped silicon layer.

Therefore, the second n-type diffusion layer of n-type SGT and thesecond p-type diffusion layer of p-type SGT can be electricallyconnected to each other by forming a silicide on a portion of the planarsilicon layer serving as the element formation region, the portion beingformed around a first side of the gate line. As a result, the width ofthe planar silicon layer serving as the element formation region can benarrowed as compared with when a silicide is formed on portions of anelement formation region around both opposing sides of gate line. Sincethe planar silicon layer serving as the element formation region has anarrow width, a highly integrated CMOS SGT inverter can be realized.

According to the embodiment of the present invention, the firstinsulating film sidewall is formed on the sidewall of the first gateline, and the silicide is formed over the second n-type diffusion layerand the second p-type diffusion layer. Further, the first predeterminedamount is larger than a value obtained by subtracting a length of halfthe width of the first planar silicon layer from the total of the widthof the first insulating film sidewall and a length of half the width ofthe first gate line. Thus, a silicide can be formed on a portion of theplanar silicon layer serving as the element formation region, theportion being present around a first side of gate line.

According to the embodiment of the present invention, an upper portionof the second gate electrode is covered with the third insulating filmsidewall, and the sidewall is covered with the first insulating filmsidewall. The sidewall of the third insulating film sidewall is coveredwith the first insulating film sidewall. Therefore, when the contactformed on the diffusion layer in an upper portion of the planar siliconlayer is offset to the second gate electrode side (relative position isshifted), short-circuiting between the second gate electrode and thecontact can be prevented.

According to the embodiment of the present invention, a CMOS SGTstructure having a narrow planar silicon layer serving as an elementformation region can be provided. This can provide highly-integratedSRAM.

According to the embodiment of the present invention, the 12th (second)n-type diffusion layer of n-type SGT and the 12th (second) p-typediffusion layer of p-type SGT can be electrically connected to eachother by forming a silicide in a portion of the 11th (first) planarsilicon layer serving as the element formation region, the portion beingpresent around a first side of the 11th (first) gate line. Also, aportion of the 11th (first) planar silicon layer serving as the elementformation region, the portion being present around a second side of the11th (first) gate line, is covered with the 11th (first) gate line andthe 11th (first) insulating film sidewall. Therefore, the 11th (first)contact is formed over a portion between the 11th (first) pillar-shapedsilicon layer and the 12th (second) pillar-shaped silicon layer and aportion between the 21st (fifth) pillar-shaped silicon layer and the22nd (sixth) pillar-shaped silicon layer, thereby permitting electricconnection between the 11th (first) gate line and the 21st (fifth)planar silicon layer through the 11th (first) contact and insulation ofthe 11th (first) planar silicon layer from the 11th (first) contact.

According to the embodiment of the present invention, input and outputof a SRAM inverter can be electrically connected through the 11th(first) contact. Therefore, highly-integrated SRAM can be provided.

In the present invention, various embodiments and modifications can bemade without deviating from the broad spirit and scope of the presentinvention. The above-described embodiments are illustrative of anexample of the present invention and do not limit the scope of thepresent invention.

For example, the technical scope of the present invention, of course,includes a method for manufacturing a semiconductor device in whichconductivity types are reversed from the p-type (including p+-type) andthe n-type (n+-type) in the above-described embodiments, and asemiconductor device manufactured by the method.

1. A semiconductor device, comprising: a first planar silicon layerformed in a first row of coordinates of rows and columns arranged on asubstrate so as to extend in a row direction; a first pillar-shapedsilicon layer formed on the first planar silicon layer to be disposed inthe first row and a first column of the coordinates; a first gateinsulating film formed around the first pillar-shaped silicon layer; afirst gate electrode formed around the first gate insulating film; afirst second-conductivity-type diffusion layer formed in an upperportion of the first pillar-shaped silicon layer; a secondsecond-conductivity-type diffusion layer formed over a lower portion ofthe first pillar-shaped silicon layer and an upper portion of the firstplanar silicon layer; a second pillar-shaped silicon layer formed on thefirst planar silicon layer to be disposed in the first row and thesecond column of the coordinates; a second gate insulating film formedaround the second pillar-shaped silicon layer; a second gate electrodeformed around the second gate insulating film; a firstfirst-conductivity-type diffusion layer formed in an upper portion ofthe second pillar-shaped silicon layer; a second first-conductivity-typediffusion layer formed over a lower portion of the second pillar-shapedsilicon layer and an upper portion of the first planar silicon layer; athird pillar-shaped silicon layer formed on the first planar siliconlayer to be disposed in the first row and the third column of thecoordinates; a third gate insulating film formed around the thirdpillar-shaped silicon layer; a third gate electrode formed around thethird gate insulating film; a third second-conductivity-type diffusionlayer formed in an upper portion of the third pillar-shaped siliconlayer; a fourth second-conductivity-type diffusion layer formed over alower portion of the third pillar-shaped silicon layer and an upperportion of the first planar silicon layer; a first gate line connectedto the first and second gate electrodes; a fifth planar silicon layerformed in the second row of the coordinates arranged on the substrate; afifth pillar-shaped silicon layer formed on the fifth planar siliconlayer to be disposed in the second row and the first column of thecoordinates; a fifth gate insulating film formed around the fifthpillar-shaped silicon layer; a fifth gate electrode formed around thefifth gate insulating film; a fifth second-conductivity-type diffusionlayer formed in an upper portion of the fifth pillar-shaped siliconlayer; a sixth second-conductivity-type diffusion layer formed over alower portion of the fifth pillar-shaped silicon layer and an upperportion of the fifth planar silicon layer; a sixth pillar-shaped siliconlayer formed on the fifth planar silicon layer to be disposed in thesecond row and the second column of the coordinates; a sixth gateinsulating film formed around the sixth pillar-shaped silicon layer; asixth gate electrode formed around the sixth gate insulating film; afifth first-conductivity-type diffusion layer formed in an upper portionof the sixth pillar-shaped silicon layer; a sixthfirst-conductivity-type diffusion layer formed over a lower portion ofthe sixth pillar-shaped silicon layer and an upper portion of the fifthplanar silicon layer; a seventh pillar-shaped silicon layer formed onthe fifth planar silicon layer to be disposed in the second row and thethird column of the coordinates; a seventh gate insulating film formedaround the seventh pillar-shaped silicon layer; a seventh gate electrodeformed around the seventh gate insulating film; a seventhsecond-conductivity-type diffusion layer formed in an upper portion ofthe seventh pillar-shaped silicon layer; a eighthsecond-conductivity-type diffusion layer formed over a lower portion ofthe seventh pillar-shaped silicon layer and an upper portion of thefifth planar silicon layer; and a fifth gate line connected to the sixthand seventh gate electrodes, wherein a center line extending along thefirst gate line is offset to the second row of the coordinates by afirst predetermined amount from a line connecting a center of the firstpillar-shaped silicon layer and a center of the second pillar-shapedsilicon layer; and a center line extending along the fifth gate line isoffset to the first row of the coordinates by the first predeterminedamount from a line which connects a center of the sixth pillar-shapedsilicon layer and a center of the seventh pillar-shaped silicon layer.2. The semiconductor device according to claim 1, further comprising: afirst insulating film sidewall formed on a sidewall of the first gateline; and a silicide formed over the second second-conductivity-typediffusion layer and the second first-conductivity-type diffusion layer,wherein the first predetermined amount is larger than a value obtainedby subtracting a length of half the width of the first planar siliconlayer from the total of the width of the first insulating film sidewalland a length of half the width of the first gate line.
 3. Thesemiconductor device according to claim 2, wherein a first contact isformed over a portion between the first pillar-shaped silicon layer andthe second pillar-shaped silicon layer and a portion between the fifthpillar-shaped silicon layer and the sixth pillar-shaped silicon layer;and the first gate line is electrically connected to the fifth planarsilicon layer through the first contact.
 4. The semiconductor deviceaccording to claim 1, wherein the first predetermined amount is greaterthan a value obtained by subtracting a total of the width of the firstinsulating film sidewall and a length of half the width of the firstgate line from half the width of the first planar silicon layer.